1. Field of the Invention
The present invention pertains to diaphragms for filter press cells. More particularly, the present invention pertains to the manufacture of diaphragms for filter press cells. Even more particularly, the present invention pertains to the manufacture of a plurality of diaphragms for filter press cells at a single time.
2. Prior Art
The use of diaphragms in composite filter press cells, i.e., bipolar and monopolar, has been well documented heretofore. Such diaphragms, generally, comprise a support surface having deposited thereon a suitable non-conductive material, e.g., asbestos, fibrous material and polymeric material. Conventionally, these diaphragms are made or manufactured on a piecemeal basis, i.e., one at a time.
A plurality of methods have been developed for manufacturing diaphragms on an individual basis. For example, U.S. Pat. No. 1,372,118 teaches a method for producing an asbestos diaphragm wherein an asbestos slurry is deposited on a support screen. The slurry is densified by the use of varying vacuums and superatmospheric pressure. In U.S. Pat. No. 1,855,497 there is disclosed a deposit box for the manufacture of asbestos diaphragms wherein the fingers of the cathode downwardly depend into the interior of the box. Perforated feed pipes traverse the interior of the deposit box for introduction of water thereinto. According to this reference, dry asbestos is placed in the tank and, then, water is introduced thereinto to form a slurry. The cathode is, then, inserted into the box and the water is turned on full. A partial vacuum is then applied to pull off the water. After the water level is normalized, a greater vacuum, then, is applied. The slurry is, then, compacted by the application of a full vacuum across the cathode away from the slurry deposit box.
Other background art is found in U.S. Pat. Nos. 1,910,771 and 3,505,200.
However, it is to be appreciated from the prior art that there has not heretofore been taught the manufacture of a plurality of diaphragms at any one time. It is to this which the present invention is directed.